Summary

In the described trials the influence of biodynamic preparations and also of different kinds and intensities of fertilization on potatoes were investigated. It was observed that: — an increase of fertilizer enlarged the total yield, the average tuber weight, the total carbohydrate content, the weight loss in store and the tendency to self-digestion, — the higher intensity of fertilization also reduced the tissue strength, the content of dry matter and the share of saccharose. — In comparison to biodynamic and organic fertilizer the mineral fertilizer reduced the content of dry matter and increased the total yield, the average tuber weight, the self-digestion, conductivity and the tendency to build germs. — Biodynamic preparations influenced the number of flowers and the content of carbohydrates without a clear tendency, reduced the relation between leaf-surface and -dimensions and raised the tissue strength. After all it is still not quite clear, under which circumstances the preparates are effective and why they sometimes show contrary effects. A lot more parameters are still waiting to be analyzed, for example some more contents like ascorbic acid, nitrate and minerals. In addition to that sensoric investigations are carried out in cooperation with the „Federal Research Institute for Nutrition“ in Karlsruhe. With these results and those of the following years we expect conclusive indications to possibilities of improving quality of potatoes by means of fertilization and treatment with biodynamic preparations.